What's the plural form of trichromatism? Here's the word you're looking for.
Answer
The noun trichromatism can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be trichromatism.
However, in more specific contexts, the plural form can also be trichromatisms e.g. in reference to various types of trichromatisms
or a collection of trichromatisms.
Examples
Position and brightness are two generally useful clues, as well as the slight differences that may be perceived even with severe anomalous trichromatism.